SQL & PL/SQL

Hi,

I have an application where delimited text files are uploaded by sqlloader into temporary tables.
From here data is inserted into main table through a stored procedure.

This is a daily activity and every time temp table is truncated and new data is uploaded into it.

Now due to some syntax error in sqlloader control file,no data was loaded into temp table ans so too in main table for last 15 days.
There is statement in the proceudre as:

select filedate into fdate from temp_table;

Today the statement threw error "no data found",since temp table was empty.
Logically error was should have been reported the very first day as since temp table was empty then also.But how come it throws error suddenly.

Nothing has changed for last 1 month in the application except the change in control file which caused error.

I need to explain my superiors why didn't the error appear on 1st day itself,since we have to re-upload the files again.
Please reply.
Thanks.